I had a problem with shoryukens and tatsumaki's and the like when I was younger but I learned that a Shoryuken is just simply: Forward, Down, Forward, Punch. You don't even need to slide your fingers across the d-pad as the command list graphic would have you do it. You could even try chicken pecking it with your index finger as practice and you'll get the muscle memory for it eventually!
My current bane in fighting games is doing more than one consecutive half circle directional input in mid-air, just to do a character's special attack, which has prevented me from using one of my favorite King of Fighter characters, Leona, in any serious battles.